JPS61260165A - Sampling monitor for automatic chemical analyzer - Google Patents

Abstract

PURPOSE:To make possible the exact monitoring by obtaining the respective pressure data in the stage when a sampling nozzle is open to the atm. and in the stage when said nozzle sucks or discharges a specimen and obtaining the difference therebetween. CONSTITUTION:The sampling nozzle 1 is held open to the atm. and a prescribed amt. of deaerated water is sucked by a sampling tube 38B into a dispensing pump 39. The suction pressure of the pump 39 in this stage is transmitted via a sampling tube 38A, a 3-way valve 36 and a pressure transmission tube 41 into a pressure sensor 21, by which said pressure is detected. An analog-to-digital converter 22 fetches the output data of a pressure sensor 36 in this stage. The fetched data is subjected to analog-to-digital conversion and is stored 23 as an A/D value PW. A slight amt. of air is sucked into the nozzle 1 and thereafter the nozzle 1 is driven 35 to be put into a sampling cup 2 and to suck the specimen of the amt. equal to the amt. of the diluting water in the deaerated water, by which an A/D value PS is obtd. A CPU23 makes calculation in accordance with the A/D value PS and the preliminarily stored A/D value PW. The result thereof is displayed as the zero-corrected A/D value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a sampling monitor for an automatic chemical analyzer that accurately detects the state of suction and discharge operations by a sampling nozzle.

[Technical background of the invention and its problems] In an automatic chemical analyzer, sampling is performed in which a sample is transferred from one container to another using a sampling nozzle in order to dilute or dispense the sample. .

A conventional liquid level sensor is generally used as a sampling monitor to monitor the state of sampling.

As this liquid level sensor, an electric sensor that takes advantage of the initiative of the sample and changes in electrical resistance depending on the amount of sample, and a temperature sensor that uses the difference between the temperature of the sensor itself and the liquid temperature of the sample are used. ing.

However, in the case of electric sensors, there is a constraint that the target specimen must have electrical conductivity above a certain level.

Furthermore, in the case of a temperature sensor, there is a constraint that the liquid temperature of the sample and the normal temperature of the sensor itself must be at least a certain distance apart.

Furthermore, compared to the case where only the sampling nozzle 1 is lowered into the sampling cup 2 and the sample 11 is aspirated as shown in FIGS. Therefore, the diameter of the sampling cup 2 must be increased, and the amount of sample required for dispensing the sample 11 without dilution, which is not used for automated chemical analysis, increases. be.

Furthermore, as shown in FIG. 6, the specimen 11 remains between the sampling nozzle 1 and the liquid level sensor 12, and the next specimen 1
Carryover or cross-contamination may occur between the specimen 1A and the sample 11, as shown in FIG. There is a problem in that the sampling nozzle 1 is clogged with the solid matter 13, making it impossible to inhale and discharge the specimen 11.

To solve these drawbacks of the liquid level sensor, devices using a pressure sensor that detects the pressure when the sample 11 is inhaled and discharged have also been used.

However, since the sampling monitor using this pressure sensor only uses the absolute value of the suction pressure of the sample, the pressure caused by dirt or bends in the tube connected to the sampling nozzle is added to the suction pressure, making it normal. The absolute value of the suction pressure of the sample may be affected by such factors as a sealed location, a high altitude location, or changes in atmospheric pressure due to weather, which may cause an error in the measurement result. There is a problem in that correct determination cannot be made due to a number of factors, including aging of the resistance value customer, which has a negative effect on the measurement results.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and is intended to improve the aging of GA components, electric circuits, and the outside world. It is an object of the present invention to provide a sampling monitor for an automatic chemical analyzer that can eliminate the effects of changes in atmospheric pressure and the like and make accurate judgments.

[Summary of the Invention 1] The present invention for achieving the above object has a sampling nozzle and a pressure sensor that detects the pressure when a sample is inhaled or discharged by the sampling nozzle, and the pressure detected by the pressure sensor is based on the pressure detected by the pressure sensor. In a sampling monitor of an automatic chemical analyzer that determines the sampling state of a sampling nozzle, an analog-digital system that digitizes two pressure data from a pressure sensor when the sampling nozzle is open to the atmosphere and when a sample is inhaled or discharged. The present invention is characterized by comprising a converter and an arithmetic processing means that performs correction corresponding to the atmospheric pressure at the time of measurement based on two pieces of digitized pressure data to obtain pressure data.

[Embodiments of the Invention] The present invention will be described in detail below. The embodiment device shown in FIG. 1 includes a sampling system unit 20 for inhaling and discharging specimens, dilution water, washing water, etc. provided in an automatic chemical analysis line, and a sampling nozzle 1 in the sampling system unit 20. A pressure sensor 21 that detects pressure and discharge pressure, and A/ that converts the output data of the pressure sensor 21 into numerical values.
It has a D (analog-digital) converter 22 and a CPU (computer unit) 23 that processes the output of the A/D converter 22.

The sampling system unit 20 includes the sampling nozzle 1
The drive motor 2 is attached to the nozzle holder 24 that supports the
a nozzle elevator 27 that moves the sampling nozzle 1 up and down by transmitting the rotational force of 5 through a gear 26;
The cylindrical body 28 fixed to the nozzle elevator 27 is fitted into the horizontally arranged sampling arm 29, and the driving pulley 31 fixed to the driving shaft 30a of the horizontal drive motor 30 and the driven pulley arranged further outside the nozzle elevator 27. By connecting the strip 33 stretched between the nozzle holders 24 and 32 to the nozzle holder 24.

A nozzle drive unit 35 consisting of a horizontal drive mechanism 34 that drives the nozzle elevator 27 in the horizontal direction, a three-way valve 36 and a two-way switchable solenoid valve 37 are connected to each other in the piping by a first sampling tube 38A. A dispensing pump 39 communicating with the sampling nozzle 1 and a solenoid valve 3
7, the suction pressure and discharge pressure of the dispensing pump 39 are transmitted, and the tip of the second sampling tube 38B is connected to a deaerated water cup 40 that stores deaerated water. It's coming inside.

The electromagnetic valve 37 is attached to the dispensing pump 39, and the three-way valve 36 is attached to the pressure sensor 21. Furthermore, a pressure transmission tube 41 connected between the three-way valve 36 and the pressure sensor 21 is filled with fluid silicone, and transmits the pressure within the first sampling tube 38A to the pressure sensor 21. A work that prevents the pressure sensor 21 from being influenced when the suction pressure and discharge pressure from the dispensing pump 39 are transmitted to the sampling nozzle 1. ,ru.

The A/D converter 22 has an 8-bit (o to 255)
The pressure sensor 21. Yo. Detection pressure 4a/c
The A/D value is set to 1 for n2.

This A/D: + inverter 22 is a pressure sensor 21
The pressure-voltage converted voltage value is converted into a digital value and output.

The CPU 23 receives A/D from the A/D converter 22.
The calculation according to the following equation (1) is executed using D11 as the base, and the calculation result is sent to a printer or TV monitor (not shown).

Pj = Ps - Pw ・[1
) Here, Ps is the A/D value corresponding to the suction pressure when the sampling nozzle 1 sucks the sample, ρW is the A/D value corresponding to the suction pressure when the sampling nozzle 1 is open to atmosphere,
Pj is an A/D value subjected to zero correction (correction corresponding to the measurement environment) obtained by calculating the above equation (1).

In the above-described embodiment apparatus, the inner diameter of the tip of the sampling nozzle 1 is 0.425 nv, and the inner diameter of the first and second sampling tubes 38A and 38B is 1.5 gg.
+, deaerated water intake is 625111/sac.

Inhalation of the specimen shall be carried out under conditions such as 375 μl/SeO.

Next, the operation of the device having the above configuration will be explained. The first state is the initial state. The second sampling tubes 38A, 38B, the sampling nozzle 1 and the dispensing pump 39 are filled with degassed water, and the tip of the sampling nozzle 1 is located above the drain cup 42 provided along the line of the device. It is assumed that

First, the solenoid valve 37 is switched so that the dispensing pump 39 sucks degassed water through the second sampling tube 38B.

At this time, sampling nozzle 1. One end of the first sampling tube 38A is closed by the Wit valve 37, and the sampling nozzle 1 at the other end is opened to the atmosphere.

Next, the dispensing pump 39 is driven, and a predetermined amount of degassed water is sucked into the dispensing pump 39 as dilution water A and washing water B through the second sampling tube 38B.

At this time, the suction pressure of the dispensing pump 39 is transmitted to the pressure sensor 21 via the first sampling tube, the three-way valve 36, and the pressure transmission tube 41, and is detected. The A/D converter 22 takes in the output data of the pressure sensor 36 at this time, performs A/D conversion, and sends the result to CPtJ2.
Send to 3.

The CPU 23 stores this AID value as a base value pw.

Next, the solenoid valve 37 is switched. Then, the cleaning water A and dilution water B in the dispensing pump 39 are connected to the deaerated water filling the sampling tube 38A in the initial state, and if the discharge operation is started, the deaerated water in the dispensing pump 39 is connected. The liquid amounts of water A and dilution water B correspond to the liquid amounts of degassed water from the tip of the sampling nozzle 1 as shown in FIGS. 2(a) and 2(b).

Next, leave the solenoid valve 37 as it is and open the dispensing bomb 39.
After sucking a small amount of air into the sampling nozzle 1 on the drain cup 42, the nozzle drive mechanism 35 is further driven to place the sampling nozzle 1 into the sampling cup 2, as shown in FIG. 2(b). Inhale the sample 11 in an amount equal to the dilution water A. The purpose of inhaling air into the sample 11 is to prevent the sample 11 from mixing with the dilution water A.

The suction pressure of the specimen 11 by the sampling nozzle 1 is the first
The pressure is transmitted to the pressure sensor 21 via the sampling tube 38A, the three-way valve 36, and the pressure transmission tube 41, and is detected. The output data of the pressure sensor 21 is converted into an A/D value by the A/D converter 22 and then taken into the CPU 23 as the A/D value Ps when the sample 11 is inhaled.

The CPU 23 executes the calculation according to the formula (1) based on this A/Dl[Ps and the A/D (direct pw) stored in advance, and uses this result as the zero-corrected A/D value Pj. It is sent to a display means and displayed.

After inhaling the specimen 11, the horizontal drive mechanism 3 drives the nozzle elevator 27 to raise the sampling nozzle 1.
4, the sampling nozzle 1 is moved onto the reaction cup 43 provided along the line.

Then, the dispensing pump 39 is driven again to discharge the sample 11 and dilution water A into the reaction cup 43. Thereby, the specimen 11 is diluted two times.

Thereafter, the sampling nozzle 1 is further moved onto the drain cup 42 by the horizontal driving efi 4434, and the dispensing pump 39 is driven to discharge the cleaning water B into the drain cup 42. As a result, the inside of the sampling nozzle 1 and the first sampling tube 38A is cleaned.

A/D II P corrected to zero by the above procedure
j is required.

A/D (direct Pj
Errors due to aging due to mechanical parts, electrical parts, etc. of the apparatus and differences in the measurement environment are removed, and the value becomes exactly proportional to the viscosity of the sample 11, as shown in FIG. still,
In this figure, the horizontal axis represents the viscosity of serum as specimen 11, and the vertical axis represents A.
/ D (!! Viscosity of serum obtained from the human body using P j - 8 / Diti P j) The standard corresponding range is shown in the shaded area, and the viscosity of standard serum whose viscosity is known in advance - A/D(iiPj) (D relationship is shown by a broken line. From the same figure, it is clear that a proportional relationship holds between A/D value Pj and viscosity. In addition, FIG. , A/D value Pj obtained for water, pooled serum, and standard serum, with the number of measurements N = 10.
It is clear from the figure that the AZD values in each case are reproducible.

Therefore, from the relationship between A/DliiPj and viscosity shown in Fig. 3, if A/DiPj is above a certain value, the sample 1
It can be determined that the viscosity of the sampling nozzle 1 is abnormally high or that solid matter has entered the sampling nozzle 1 and normal suction operation cannot be performed.

On the other hand, if the A/D value Pj is below a certain value, it can be determined that the viscosity of the sample 11 is abnormally low.Furthermore, if the A/D value Pj is close to zero, it can be determined that the viscosity of the sample 11 is abnormally low. Air is sucked in at the end of the suction operation of the sampling nozzle 1, and therefore it can be determined that the suction operation is not being performed normally.

The present invention is limited to the embodiments described above.1. Yonaku,
Various modifications are possible within the scope of the gist.

For example, in the above-described embodiment, the case where the sample is diluted twice is explained, but any dilution ratio can be used.

Also, from sampling cup 2 to sampling nozzle 1
In addition to the case in which the sample inhaled by the sample is discharged into one reaction cup as in the embodiment device, an arbitrary amount may be discharged into any other arbitrary number of reaction cups.

Furthermore, we have explained the case where degassed water is sucked into the second sampling tube and used as dilution water and washing water.
As shown in FIG. 1, a water absorption cup 44 storing degassed water can be arranged along a line, and the degassed water can be drawn directly from the water absorption cup 44 using a sampling nozzle to be used as dilution water or cleaning water.

Furthermore, in addition to using the suction pressure when the sample is aspirated by the sampling nozzle, it is also possible to set another reference value and obtain A/DI using the discharge pressure when the sample is discharged. .

Effects of the Invention] According to the present invention detailed above, pressure data is obtained when the sampling nozzle is open to the atmosphere and when the sample is sucked or discharged, and the difference between these data is calculated. It is possible to provide a sampling monitor for an automatic chemical analyzer that can perform accurate monitoring while eliminating the effects of aging and environmental conditions on mechanical parts and electrical parts of the apparatus.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an embodiment device of the present invention;
Figure 2 (a) is a cross-sectional view of the sampling nozzle of the same device showing the state in which dilution water and washing water are sucked in, and Figure 2 (b) is a cross-sectional view showing the state shown in Figure 2 (a) when air and sample are further sucked in. 3rd cross-sectional view showing the sampling nozzle
The figure is a graph showing the relationship between the A/D value and the viscosity of the sample obtained by the example device, and Figure 4 is a table showing the reproducibility of the A/D value in various conditions obtained by the example device. Figure 5 (a) is a front view showing the sampling nozzle inhaling the specimen from the sampling cup, Figure 5 (b) is a front view showing the relationship between the sampling nozzle, liquid level sensor, and sampling cup, and Figure 6 is Fig. 7 is a front view showing a state in which different specimens are inhaled using a sampling nozzle and a liquid level sensor, and Fig. 7 is a front view showing a state in which the sampling nozzle is clogged with solid matter. 1... Squeezing nozzle; 11... Specimen, 20...
...Sampling system unit, 21...Pressure sensor, 22...A/D converter,
23...CPU, 27...Nozzle elevator, funeral 3
Figure 6 Figure 7

Claims (2)

[Claims] (1) Sampling of an automatic chemical analyzer that has a sampling nozzle and a pressure sensor that detects the pressure when a sample is inhaled or discharged by the sampling nozzle, and determines the sampling state of the sampling nozzle based on the pressure detected by the pressure sensor. In the monitor, an analog-to-digital converter digitizes the two pressure data from the pressure sensor when the sampling nozzle is open to the atmosphere and when the sample is inhaled or discharged, and a 1. A sampling monitor for an automatic chemical analyzer, comprising: arithmetic processing means for obtaining pressure data corrected to correspond to atmospheric pressure at the time of measurement. (2) The arithmetic processing means calculates the formula Pj, where Pw is the digitized pressure data corresponding to the time of opening to the atmosphere, Ps is the digitized pressure data corresponding to the time of sample inhalation, and Pj is the corrected pressure data. A sampling monitor for an automatic chemical analyzer according to claim 1, which performs the calculation of =Ps-Pw.